Display control device, display device, display control method, and non-transitory storage medium

ABSTRACT

A display control device includes an obtainer and a controller. The obtainer obtains a detection accuracy of an object that exists in surroundings of a movable body. When the obtainer obtains a first detection accuracy, the controller controls an image generator so as to generate a first predetermined image that shows a first graphic having a predetermined shape and divided into n regions (n is an integer greater than or equal to 2). When the obtainer obtains a second detection accuracy that is lower than the first detection accuracy, the controller controls the image generator so as to generate a second predetermined image that shows a second graphic having a predetermined shape and undivided or divided into m regions (m is an integer that is greater than or equal to 2 and that is smaller than n).

BACKGROUND

1. Technical Field

The present disclosure relates to a display control device and a displaycontrol method that control display of information provided to anoccupant in a vehicle or the like and to a display device and anon-transitory storage medium.

2. Description of the Related Art

Recent years have seen active development of a driving assistance systemthat detects an object (e.g., a vehicle, a pedestrian, a white line, aroad sign, or the like) that exists in the surroundings of a vehicle byusing a sensor mounted thereon and that presents information to anoccupant in the vehicle upon determining that the possibility ofcollision with the object is high.

In an environment where the vehicle travels, however, there are cases inwhich the accuracy with which the sensor detects an object in thesurroundings of the vehicle changes (this accuracy is hereinafterreferred to as “sensing accuracy”). One example of a method for changinginformation presentation to the occupant in accordance with the sensingaccuracy is a technology disclosed in Japanese Unexamined PatentApplication Publication No. 2009-117978 (hereinafter referred to as“related art”).

In the related art, during display of an image captured by avehicle-mounted camera, an object included in the image is highlightedaccording to the degree of reliability of recognition accuracy of theobject. This makes it possible to avoid giving the occupant a sense ofdiscomfort due to an event in which information being displayed issuddenly not displayed when the sensing accuracy decreases.

However, although, in the related art, an object is highlightedaccording to the sensing accuracy, no consideration is given to thesensing accuracy.

SUMMARY

One non-limiting and exemplary embodiment provides a display controldevice and a display control method that allow an occupant in a movablebody to intuitively recognize the sensing accuracy and also provides adisplay device and a non-transitory storage medium.

In one general aspect, the techniques disclosed here feature a displaycontrol device in a display system including a detection device thatdetects a predetermined object that exists in surroundings of a movablebody, a calculator that calculates a detection accuracy of the detectiondevice, an image generator that generates a predetermined image, and adisplayer that outputs the predetermined image on a display medium todisplay a graphic having a predetermined shape on the display medium.The display control device includes: an obtainer that obtains thedetection accuracy; and a controller that controls, based on thedetection accuracy, the image generator so as to generate thepredetermined image that shows the graphic having a predetermined shapewhen displayed on the display medium. The controller controls the imagegenerator so as to generate a first predetermined image as thepredetermined image, when the obtainer obtains a first detectionaccuracy, and controls the image generator so as to generate a secondpredetermined image as the predetermined image, when the obtainerobtains a second detection accuracy lower than the first detectionaccuracy. The first predetermined image shows, as the graphic having apredetermined shape, a first graphic divided into n regions whendisplayed on the display medium, and the second predetermined imageshows, as the graphic having a predetermined shape, a second graphicdivided into m regions or undivided when displayed on the displaymedium, where n is an integer greater than or equal to 2, and m is aninteger that is greater than or equal to 2 and that is smaller than n.

According to the present disclosure, an occupant in a movable body canintuitively and visually recognize the sensing accuracy.

It should be noted that general or specific embodiments may beimplemented as a system, a method, an integrated circuit, a computerprogram, a storage medium, or any selective combination thereof.

Additional benefits and advantages of the disclosed embodiments willbecome apparent from the specification and drawings. The benefits and/oradvantages may be individually obtained by the various embodiments andfeatures of the specification and drawings, which need not all beprovided in order to obtain one or more of such benefits and/oradvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example configuration of adisplay system according to a first embodiment of the presentdisclosure;

FIG. 2 is a block diagram illustrating an example configuration of thedisplay system according to the first embodiment of the presentdisclosure;

FIG. 3 is a flowchart illustrating an example operation of the displaysystem according to the first embodiment of the present disclosure;

FIG. 4 illustrates a display example of an image according to the firstembodiment of the present disclosure;

FIGS. 5A to 5F illustrate examples of dividing the image according tothe first embodiment of the present disclosure;

FIGS. 6A to 6F illustrate examples of dividing the image according tothe first embodiment of the present disclosure;

FIGS. 7A to 7D illustrate examples of a table and highlighting accordingto the first embodiment of the present disclosure;

FIGS. 8A to 8D illustrate examples of a table and highlighting accordingto the first embodiment of the present disclosure;

FIGS. 9A to 9F illustrate examples of dividing an image according to thefirst embodiment of the present disclosure;

FIGS. 10A to 1OF illustrate examples of dividing the image according tothe first embodiment of the present disclosure;

FIGS. 11A to 11F illustrate examples of dividing the image according tothe first embodiment of the present disclosure;

FIG. 12 is a block diagram illustrating an example configuration of adisplay system according to a second embodiment of the presentdisclosure;

FIG. 13 is a block diagram illustrating an example configuration of adisplay system according to a third embodiment of the presentdisclosure;

FIG. 14 is a flowchart illustrating an example operation of the displaysystem according to third embodiment of the present disclosure;

FIGS. 15A to 15C illustrate examples of a luminance setting pattern andan image transition according to the third embodiment of the presentdisclosure;

FIG. 16 is a block diagram illustrating a hardware example configurationof the display control systems and display control devices according tothe first to third embodiments of the present disclosure;

FIG. 17 is a block diagram illustrating another example configuration ofthe display system according to the first embodiment of the presentdisclosure;

FIGS. 18A to 18C illustrate examples of dividing the image according tothe first embodiment of the present disclosure

FIG. 19 illustrates an example of dividing the image according to thefirst embodiment of the present disclosure;

FIG. 20 illustrates one example of a combiner according to the firstembodiment of the present disclosure;

FIG. 21 is a flowchart illustrating an example operation of the displaycontrol device in the display system illustrated in FIG. 17;

FIG. 22 is a flowchart illustrating another example operation of thedisplay control device in the display system illustrated in FIG. 17;

FIGS. 23A and 23B illustrate examples of dividing the image according tothe first embodiment of the present disclosure;

FIGS. 24A to 24D illustrate examples of dividing the image according tothe first embodiment of the present disclosure; and

FIGS. 25A to 25D illustrate examples of dividing the image according tothe first embodiment of the present disclosure.

DETAILED DESCRIPTION

In known driving assistance systems, for example, when a camera is usedas a sensor, the sensing accuracy may decrease in driving environments,such as at night, in backlight, and in rainy weather. In known drivingassistance systems, for example, when a millimeter-wave radar is used asa sensor, the sensing accuracy may also decrease in driving environmentswhere an obstruction that reflects radar waves exists. If informationpresentation that is the same as typical information presentation isperformed for the occupant in spite of the situation in which thesensing accuracy has decreased, there is the possibility that anerroneous warning is issued or no warning is issued. Thus, it isimportant for the occupant to recognize the decrease in the sensingaccuracy. Accordingly, embodiments of the present disclosure allow theoccupant to recognize the sensing accuracy.

First Embodiment

A first embodiment of the present disclosure will be described withreference to the accompanying drawings.

First, a description will be given of an example configuration of adisplay system 10 according to the present embodiment. FIG. 1 is a blockdiagram illustrating an example configuration of the display system 10according to the present embodiment.

The display system 10 is used, for example, in a movable body, such as avehicle. That is, the display system 10 may be vehicle-mounted equipmentor may be equipment that is carried into a vehicle. Although adescription in the present embodiment will be given assuming that thedisplay system 10 is applied to a vehicle, the movable body is notlimited to a vehicle and may be a ship, an airplane, or the like.Although a description in the present embodiment will be given of anexample in which a user is an occupant in a vehicle, particularly thedriver of a vehicle, the user is not limited thereto. In addition, thedisplay system 10 may also be used for a wearable computer (e.g., an HMDdescribed below) that a user can wear on his or her body.

In FIG. 1, the display system 10 includes a sensor 100, a recognizer200, a calculator 300, a display control device 400, an image generator500, and a displayer 600. The display control device 400 has adeterminer 401 and a display controller 402.

The sensor 100 may also be included in a detection device (see FIG. 17).The recognizer 200 may also be included in the detection device (seeFIG. 17) in conjunction with the sensor 100. The display control device400 may also include an obtainer (see FIG. 17). Examples of the obtainerinclude an input terminal, a connector and a signal input unit. Thedeterminer 401 and the display controller 402 may also be combinedtogether to serve as a controller (see FIG. 17).

FIG. 17 illustrates another example configuration of the display system10. This display system 10 includes a detection device 700, a calculator300, a display control device 400, an image generator 500, and adisplayer 600. The display control device 400 has an obtainer 404 and acontroller 405. A display device 20 has the display control device 400,the image generator 500, and the displayer 600. Details of the displaysystem 10 illustrated in FIG. 17 are described later.

The constituent elements of the display system 10 will be describedbelow with reference to FIG. 1.

The sensor 100 senses the forward view of the driver of the vehicle atpredetermined time intervals. The sensor 100 is, for example, a sensingcamera. The sensing camera is installed inside or outside the vehicle tocapture an image of the forward view of the vehicle. In addition, thesensing camera may capture not only an image of the forward view butalso images of the side views. Alternatively, the sensor 100 may be, forexample, a radar. The radar is installed inside or outside the vehicleto sense the forward view and so on of the vehicle. The forward view andso on of the vehicle may hereinafter be referred to as “surroundings ofthe vehicle”.

The sensor 100 outputs surroundings information indicating a result ofthe surroundings sensing to the recognizer 200. This outputting isperformed, for example, at predetermined time intervals.

On the basis of the surroundings information from the sensor 100, therecognizer 200 recognizes a predetermined object that exists in thesurroundings of the vehicle. Examples of the object include a movablebody (e.g., a vehicle, a human, a bicycle, or a two-wheeled vehicle), awhite line on a road, a sign, a road surface marking, a curb, aguardrail, a traffic light, a utility pole, and a building. For example,when the sensor 100 is a sensing camera, the recognizer 200 performspattern matching or the like on the surroundings information (asurroundings image) to recognize an object. Also, for example, when thesensor 100 is a radar, the recognizer 200 extracts an object from thesurroundings information through clustering, machine learning, or thelike to recognize an object. Since the object recognition technology forthe recognizer 200 is also known art, a detailed description thereof isnot given herein.

The recognizer 200 outputs recognition result information indicating arecognition result of the object to the calculator 300 and the displaycontroller 402 in the display control device 400. The recognition resultinformation includes, for example, the position (X, Y) where an objectexists, the angle of an object relative to the traveling direction ofthe vehicle (this angle is hereinafter referred to simply as a “relativeangle”), the speed of the vehicle relative to an object (this speed ishereinafter referred to simply as a “relative speed”), an object type,information obtained by pattern matching, and information obtained byobject tracking processing. The position (X, Y) where an object existsrepresents coordinates in a camera coordinate system in which Xindicates a horizontal direction, and Y indicates a forward direction,with reference to the point where the sensing camera of the vehicle isinstalled. Y of the position (X, Y) where an object exists alsoindicates the distance between the vehicle and the object in the vehicletraveling direction (this distance is hereinafter referred to simply as“distance”).

The calculator 300 calculates a recognition accuracy of the sensor(which may also be referred to as “sensing accuracy” and is hereinafterreferred to simply as “recognition accuracy”). The calculator 300 mayalso calculate the sensing accuracy on the basis of the recognitionresult from the recognizer 200 or may also calculate the sensingaccuracy without using the recognition result obtained by the recognizer200. A description will be given below in detail.

The calculator 300 calculates the sensing accuracy, for example, on thebasis of the recognition result from the recognizer 200. Morespecifically, the calculator 300 calculates the recognition accuracy onthe basis of a difference between the surroundings image obtained duringthe pattern matching and a pre-stored template. In this case, forexample, when the difference between the image of the object captured bythe camera and the pre-stored template is small, the calculator 300calculates the recognition accuracy such that the value thereof islarge. Alternatively, for example, the calculator 300 calculates therecognition accuracy on the basis of the number of frames obtainedduring processing for tracking an object (e.g., a moving object) betweendifferent image frames. In this case, for example, the calculator 300performs the calculation such that the larger the number of frames is,the larger the value of the recognition accuracy becomes. Even when thetracking processing is successful, if the results of the objectdetection vary greatly between frames, there is the possibility that therecognition accuracy is low. Thus, the calculator 300 may perform thecalculation such that, for example, the larger the amount of change inthe detection results (the distances, the relative speeds, or the like)between frames is, the lower the recognition accuracy becomes. Also,when a device other than a camera is used as the sensor, featuresaccording to a sensor type corresponding to the aforementioneddifference between the surroundings image and the template may be usedfor the recognition accuracy calculation.

The calculator 300 may also calculate the recognition accuracy, forexample, on the basis of a recognition result of the vehicle drivingenvironment. For example, when the sensor 100 is a sensing camera, therecognizer 200 performs predetermined image processing on thesurroundings image of the vehicle captured by the sensing camera torecognize whether or not the driving environment is a drivingenvironment in which the recognition accuracy is likely to decrease(e.g., whether or not the vehicle is traveling in bad weather, such asin rain, fog, sleet, hail, or snow, whether or not the illuminance inthe surroundings of the vehicle is increased due to backlight, theheadlights of an oncoming vehicle, or the like, or whether or not theilluminance in the surroundings of the vehicle is reduced due totraveling at night or in a tunnel). When the recognizer 200 recognizesthat the driving environment is a driving environment in which therecognition accuracy is likely to decrease, the calculator 300calculates a smaller value for the recognition accuracy.

The calculator 300 may also calculate the recognition accuracy, forexample, without using the recognition result from the recognizer 200.An example in this case will now be described with reference to FIG. 2.In FIG. 2, constituent elements that are the same as or similar to thosein FIG. 1 are denoted by the same reference numerals, and descriptionsthereof are not given hereinafter. FIG. 2 is different from FIG. 1 inthat the display system 10 does not have the recognizer 200. In FIG. 2,for example, when the sensor 100 is a sensing camera, the calculator 300receives a surroundings image of the vehicle from the sensor 100. Whenthe surroundings image of the vehicle includes information indicatingthat the driving environment is a driving environment in which therecognition accuracy is likely to decrease (e.g., information indicatingthat the vehicle is traveling in bad weather, such as in rain, fog,sleet, hail, or snow, information indicating that the illuminance in thesurroundings of the vehicle is increased due to backlight, theheadlights of an oncoming vehicle, or the like, or informationindicating that the illuminance in the surroundings of the vehicle isreduced due to traveling at night or in a tunnel), the calculator 300calculates a smaller value for the recognition accuracy.

In FIG. 2, the sensor 100 may be replaced with another sensor (e.g., asensor that is substantially the same as a sensor 101 described below ina second embodiment). This sensor is, for example, a raindrop sensor oran illuminance sensor and can detect a driving environment in which therecognition accuracy is likely to decrease (e.g., whether or not thevehicle is traveling in bad weather, such as in rain, fog, sleet, hail,or snow, whether or not the illuminance in the surroundings of thevehicle is increased due to backlight, the headlights of an oncomingvehicle, or the like, or whether or not the illuminance in thesurroundings of the vehicle is reduced due to traveling at night or in atunnel). The calculator 300 receives, from the sensor, informationindicating a detection result. When the detection result indicates thatthe driving environment is a driving environment in which therecognition accuracy is likely to decrease, the calculator 300calculates a small value for the recognition accuracy.

The calculator 300 then outputs recognition accuracy informationindicating the recognition accuracy value to the determiner 401 in thedisplay control device 400.

The determiner 401 determines the recognition accuracy input from thecalculator 300. More specifically, the determiner 401 determines whetherthe recognition accuracy is high or low, on the basis of the recognitionaccuracy information from the calculator 300 and a pre-definedthreshold. For example, when the recognition accuracy value indicated bythe recognition accuracy information is larger than or equal to thethreshold (or is larger than the threshold), the determiner 401determines that the recognition accuracy is a high accuracy. On theother hand, for example, when the recognition accuracy value indicatedby the recognition result information is smaller than the threshold (oris smaller than or equal to the threshold), the determiner 401determines that the recognition accuracy is a low accuracy. Theabove-described method for the recognition accuracy determination madeby the determiner 401 is one example, and other methods are describedbelow.

After the determination, the determiner 401 outputs determination resultinformation indicating the determination result to the displaycontroller 402.

When the determiner 401 determines that the recognition accuracy is afirst recognition accuracy, the display controller 402 controls thedisplayer 600 so as to generate a predetermined image that shows agraphic having a predetermined shape and divided into n regions (n is aninteger greater than or equal to 2) when displayed on a display medium.Also, when the determiner 401 determines that the recognition accuracyis a second recognition accuracy that is lower than the firstrecognition accuracy, the display controller 402 controls the displayer600 so as to generate a predetermined image that shows a graphic havinga predetermined shape and undivided or divided into m regions (m is aninteger that is greater than or equal to 2 and that is smaller than n)when displayed on a display medium. A description will be given below indetail.

On the basis of the determination result information from the determiner401, the display controller 402 sets a division number of a pre-definedgraphic (i.e., the number of divided regions in the graphic). The“graphic” as used herein refers to image information having apredetermined shape, the image information being pre-stored by thedisplay controller 402 (or a storage unit, not illustrated), and detailsthereof are described later with reference to FIG. 4. For example, whenthe determination result information indicates a high accuracy, thedisplay controller 402 sets the division number to n (n is an integergreater than or equal to 2). On the other hand, for example, when thedetermination result information indicates a low accuracy, the displaycontroller 402 determines that the graphic is not to be divided or setsthe division number to m (m is an integer that is greater than or equalto 2 and that is smaller than n).

On the basis of the set division number, the display controller 402 alsodetermines how the graphic is to be divided (hereinafter referred to asa “dividing method”). It is assumed that the determination of thedividing method varies depending on which of the relative angle and thedistance is used to set a highlighted region described below.

Specific examples of a process for setting the division number and aprocess for determining the dividing method are described later withreference to FIGS. 4 to 6F.

The display controller 402 also sets a highlighted region, on the basisof the recognition result information from the recognizer 200. The term“highlighted region” refers to a region displayed highlighted in apost-division graphic, for example, a region indicating the direction(“relative angle”) in which an object exists or the distance(“distance”) between an object and the vehicle. The highlighted regionmay be displayed at all times or may be displayed as appropriate. Forexample, the display controller 402 sets a highlighted region in regionsthat are divided, on the basis of the relative angle indicated by therecognition result information and a pre-stored table (see FIGS. 7A and7C).

Alternatively, for example, the display controller 402 sets ahighlighted region in regions that are divided, on the basis of thedistance indicated by the recognition result information and apre-stored table (see FIGS. 8A and 8C). A specific example of theprocess for setting the highlighted region is described below withreference to FIGS. 7A to 7D and 8A to 8D.

The display controller 402 outputs control information to the imagegenerator 500. The control information is information for controllingthe image generator 500 and includes, for example, information of theshape of a graphic, the division number, the dividing method, and thehighlighted region.

The image generator 500 generates a predetermined image, on the basis ofthe control information from the display controller 402. Thepredetermined image is displayed on a display medium by the displayer600 described below and shows a graphic having a predetermined shape.

The graphic having a predetermined shape may be a circular-sector-shapedgraphic illustrated in FIGS. 4 to 6F or may be a linear graphicillustrated in FIGS. 18A to 18C. A description for FIGS. 18A to 18C isgiven later. The graphic having a predetermined shape may be any graphichaving a size to such a degree that at least the forward side relativeto the position of the driver in the movable body, the front right sideand the front left side, or the right direction and the left directioncan be distinguished when the graphic is displayed divided on a displaymedium, and the shape of the graphic does not limit the scope disclosedin the present disclosure. However, it is desirable that the graphichaving a predetermined shape be a graphic in which componentssubstantially horizontal to the horizontal axis are larger thancomponents orthogonal thereto, as illustrated in FIGS. 4 to 6F and FIGS.18A to 19. Display examples of the graphic having a predetermined shapeare described later with reference to FIGS. 4 to 6F.

The predetermined image may be an image or may be image data. When thedisplayer 600 described below has a projector function, the imagegenerator 500 generates an image, and the displayer 600 projects theimage. On the other hand, when the displayer 600 described below doesnot have a projector function, the image generator 500 generates imagedata, and the displayer 600 outputs the image data.

The displayer 600 outputs the predetermined image, generated by theimage generator 500, onto a display (which is not illustrated and is oneexample of a display medium) to thereby display the graphic having apredetermined shape on the display medium. The displayer 600 has, forexample, a projector function and directly projects the graphic onto thedisplay. The display is, for example, the front windshield of a movablebody or a transparent combiner provided separately from the windshield.That is, the displayer 600 displays a graphic having a predeterminedshape on the windshield by projecting a predetermined image onto thewindshield. The occupant in the movable body views the displayed graphichaving a predetermined shape as a virtual image. The transparentcombiner is, for example, a combiner 801 described below and illustratedin FIG. 20.

The displayer 600 may display a graphic having a predetermined shape,for example, on a display, instead of using the projector function. Inthis case, the display is a transmissive display, and the predeterminedimage generated by the image generator 500 is image data. That is, thedisplayer 600 displays a graphic having a predetermined shape on thetransmissive display by outputting image data onto the transmissivedisplay. Since the principle that image data input to a transmissivedisplay is displayed as a graphic having a predetermined shape is knownart, a description thereof is not given herein.

The display medium may also be a hologram. When a hologram is used, asystem may be used in which a light guide plate that totally internallyreflects and guides a group of parallel light beams that satisfies thetotal internal reflection condition of a light guide plate is used toemit some of a group of parallel light beams totally internallyreflected and guided in the light guide plate, to thereby allow theoccupant to view a virtual image. Although image data is not directlyprojected in a system in which a light guide plate is used, unlike aprojector, the description herein is given using the definition“projection” as in the projector system, for convenience of description.

Examples of the display include a liquid-crystal display (LCD), ahead-up display (HUD), a head-mounted display, a helmet-mounted display(HMD), an eyeglass-type display (smart glasses), a display fornavigation, a meter display, and other dedicated displays. The HUD maybe, for example, the windshield of the vehicle or a glass surface, aplastic surface, or the like that is additionally provided. For example,the windshield may be the front glass or may be a side window glass orthe rear window glass of the vehicle. In addition, the display mediummay be a transmissive display, as described above. The transmissivedisplay is, for example, a transmissive organic electroluminescent (EL)display or a transparent display employing glass that emits light uponbeing illuminated with light having a certain wavelength, and the drivercan view what is displayed on the transmissive display, at the same timeas viewing the background. The transmissive display is also a displaymedium that transmits light.

When the display medium is the windshield of a movable body, thedisplayer 600 displays a graphic having a predetermined shape on thewindshield by projecting a predetermined image onto the windshield. Whenthe display medium is a transmissive display, the predetermined image isimage data, and the displayer 600 displays a graphic having apredetermined shape on the transmissive display by outputting image dataonto the transmissive display. In the present embodiment, “output” isdefined as a superordinate concept of “projection”, for convenience ofdescription.

The display system 10 may also have a configuration including theabove-described display.

The above-described graphics may also be generated by the displaycontrol device 400 or another constituent element (not illustrated), notby the image generator 500.

For example, when the predetermined image is projected on a displaymedium, the occupant in the movable body views a graphic, generated bythe display system 10, as a virtual image. In this case, the graphic mayalso be projected onto the display so as to be superimposed on theoccupant's field of view. Since the principle that a driver views agraphic projected on a display as a virtual image is known art, adescription thereof is not given herein.

Next, a description will be given of an example operation of the displaysystem 10 according to the present embodiment. FIG. 3 is a flowchartillustrating an example operation of the display system 10 according tothe present embodiment. The flow in FIG. 3 is executed, for example, atpredetermined operation intervals, such as at intervals of 30milliseconds or 100 milliseconds. For example, when the sensor 100 is asensing camera, and the surroundings information is output to therecognizer 200 with a frame rate of 15 fps, 30 fps, or the like, theflow in FIG. 3 may be executed according to the output intervals.

In step S001, the recognizer 200 recognizes an object that exists in thesurroundings of the vehicle, on the basis of the surroundingsinformation from the sensor 100.

In step S002, the calculator 300 calculates the recognition accuracy onthe basis of the recognition result information from the recognizer 200.

In step S003, the determiner 401 determines whether the recognitionaccuracy is high or low, on the basis of the recognition resultinformation from the calculator 300 and a pre-defined threshold. Thatis, if the recognition accuracy value indicated by the recognitionresult information is larger than or equal to the threshold, thedeterminer 401 determines that the recognition accuracy is a highaccuracy (YES in step S003). In this case, the flow proceeds to stepS004. On the other hand, if the recognition accuracy value indicated bythe recognition result information is smaller than the threshold, thedeterminer 401 determines that the recognition accuracy is a lowaccuracy (NO in step S003). In this case, the flow proceeds to stepS005.

When the determination result information from the determiner 401indicates a high accuracy, in step S004, the display controller 402 setsthe division number to n (n is an integer greater than or equal to 2).

When the determination result information from the determiner 401indicates a low accuracy, in step S005, the display controller 402determines that the graphic is not to be divided or sets the divisionnumber to m (m is an integer that is greater than or equal to 2 and thatis smaller than n).

Now, specific examples of the division-number setting process and thedividing-method determination process in steps S004 and S005 will bedescribed with reference to FIGS. 4 to 6F.

First, one example of graphics generated by the display system 10 willbe described with reference to FIG. 4. In FIG. 4, a graphic 301represents the vehicle, and a graphic 302 represents the vehicle'ssurroundings (i.e., a positional relationship between the vehicle and anobject). The graphic 301 (one example of a first graphic) is not agraphic to be divided and is used as a reference position duringdetermination of the dividing method. The graphic 302 (one example of asecond graphic) is a graphic to be divided, and FIG. 4 illustrates astate before the graphic 302 is divided. The graphics 301 and 302illustrated in FIG. 4 have default shapes, and the graphics 301 and 302with these shapes are pre-stored by the display controller 402 (or astorage unit, not illustrated). The graphic 302 is also displayed at alltimes on the display with the pre-division shape illustrated in FIG. 4or with any of post-division shapes described below and illustrated inFIGS. 5A to 6F.

Next, a description will be given of setting of the division number. Forexample, the division numbers and high and low accuracies arepre-associated with each other: for example, the division number is 3for a low accuracy, and the division number is 5 for a high accuracy,and these associations are stored by the display controller 402. Thus,when the determination result information indicates a low accuracy, thedisplay controller 402 sets the division number to 3, and when thedetermination result information indicates a high accuracy, the displaycontroller 402 sets the division number to5.

After setting the division number in the manner described above, thedisplay controller 402 reads the graphics 301 and 302 illustrated inFIG. 4 and determines the dividing method.

Next, the determination of the dividing method will be described withreference to FIGS. 5A to 6F.

First, a description will be given of an example of determination of afirst dividing method. The first dividing method is a dividing methodfor a case in which the relative angle is used during setting of thehighlighted region. For example, when the division number is set 3 (m=3)in the case of a low accuracy, the display controller 402 determines adividing method for dividing the graphic 302 into three regions by usingdivision straight lines 303 extending radially from the graphic 301, asillustrated in FIG. 5A. When the displayer 600 executes this dividingmethod, the graphics are displayed on the display, as illustrated inFIG. 5B or 5C. Also, for example, when the division number is set to 5(n=5) in the case of a high accuracy, the display controller 402determines a dividing method for dividing the graphic 302 into fiveregions by using division straight lines 303 extending radially from thegraphic 301, as illustrated in FIG. 5D. When the displayer 600 executesthis dividing method, the graphics are displayed on the display, asillustrated in FIG. 5E or 5F.

Next, a description will be given of an example for determining a seconddividing method. The second dividing method is a dividing method for acase in which the distance is used during setting of the highlightedregion. For example, when the division number is set to 2 (m=2) in thecase of a low accuracy, the display controller 402 determines a dividingmethod for dividing the graphic 302 into two regions by using a divisioncurve line 304 extending in the circumferential direction of asemicircle having its center at the graphic 301, as illustrated in FIG.6A. When the displayer 600 executes this dividing method, the graphicsare displayed on the display, as illustrated in FIG. 6B or 6C. Also, forexample, when the division number is set to 3 (n=3) in the case of ahigh accuracy, the display controller 402 determines a dividing methodfor dividing the graphic 302 into three regions by using semicirculardivision curve lines 304 (in this case, a plurality of division curvelines having different radii) having their center at the graphic 301, asillustrated in FIG. 6D. When the displayer 600 executes this dividingmethod, the graphics are displayed on the display, as illustrated inFIG. 6E or 6F.

Although each of the graphics has been described above as being equallydivided, the present disclosure is not limited thereto. When thedividing method is pre-specified for each division number, it ispossible to divide the graphic by using an arbitrary dividing method.

The description above has been given of specific examples of thedivision-number setting process and the dividing-method determinationprocess. Now, a description will return to the flow in FIG. 3.

In step S006, the display controller 402 sets a highlighted region, onthe basis of the recognition result information from the recognizer 200.

Now, a specific example of the highlighted-region setting process instep S006 will be described with reference to FIGS. 7A to 7D and 8A to8D. As described above, the highlighted region is set using either therelative angle or the distance included in the recognition resultinformation from the recognizer 200.

First, the highlighted-region setting process when the relative angle isused (when the first dividing method is determined) will be describedwith reference to FIGS. 7A to 7D.

FIG. 7A illustrates an example of a first table used when therecognition accuracy is a low accuracy and the relative angle is used toset the highlighted region. The first table is pre-stored by the displaycontroller 402 (or a storage unit, not illustrated). In the first table,relative angles, which are conditions, and highlighted regions areassociated with each other. In the first table, angle A is a horizontalangle relative to the forward direction of the vehicle (or the positionof the sensor or the position of the driver), and the angle to the rightis a positive angle. For example, when the relative angle included inthe recognition result information indicates 40 degrees (A=40) to theright, the display controller 402 sets the highlighted region to aregion 603. When the displayer 600 executes this highlighted-regiondisplay process, for example, the region 603 is displayed highlighted onthe display by using color different from the color of regions 601 and602, as illustrated in FIG. 7B.

FIG. 7C illustrates an example of a second table used when therecognition accuracy is a high accuracy and the relative angle is usedto set the highlighted region. The second table is pre-stored by thedisplay controller 402 (or a storage unit, not illustrated), as in thefirst table, and relative angles, which are conditions, and highlightedregions are associated with each other. For example, when the relativeangle included in the recognition result information indicates 40degrees (A=40) to the right, the display controller 402 sets thehighlighted region to a region 607. When the displayer 600 executes thishighlighted-region display process, for example, the region 607 isdisplayed highlighted on the display by using color different from thecolor of regions 604 to 606 and 608, as illustrated in FIG. 7D.

Next, the highlighted-region setting process when the distance is used(when the second dividing method is determined) will be described withreference to FIGS. 8A to 8D.

FIG. 8A illustrates an example of a third table used when therecognition accuracy is a low accuracy and the distance is used to setthe highlighted region. The third table is pre-stored by the displaycontroller 402 (or a storage unit, not illustrated). In the third table,distances (e.g., in units of meters (m)), which are conditions, andhighlighted regions are associated with each other. For example, whenthe distance included in the recognition result information indicates 55m (D=55), the display controller 402 sets the highlighted region to aregion 702. When the displayer 600 executes this highlighted-regiondisplay process, for example, the region 702 is displayed highlighted onthe display by using color different from the color of a region 701, asillustrated in FIG. 8B.

FIG. 8C illustrates an example of a fourth table used when therecognition accuracy is a high accuracy and the distance is used to setthe highlighted region. The fourth table is pre-stored by the displaycontroller 402 (or a storage unit, not illustrated), as in the thirdtable, and distances, which are conditions, and highlighted regions areassociated with each other. For example, when the distance included inthe recognition result information indicates 55 m (D=55), the displaycontroller 402 sets the highlighted region to a region 704. When thedisplayer 600 executes this highlighted-region display process, forexample, the region 704 is displayed highlighted on the display by usingcolor different from the color of regions 703 and 705, as illustrated inFIG. 8D.

The description above has been given of a specific example of thehighlighted-region setting process.

After setting the highlighted region, the display controller 402outputs, to the displayer 600, control information for performingcontrol so that a graphic is generated and displayed on the display onthe basis of the set division number, the determined dividing method,and the set highlighted region. Now, a description will return to theflow in FIG. 3.

In step S007, on the basis of the control information from the displaycontroller 402, the displayer 600 generates the graphics and displaysthe graphics on the display. As a result, for example, the graphicsillustrated in FIGS. 7B, 7D, 8B, or 8D are displayed.

Next, a description will be given of another example configuration ofthe display system 10 illustrated in FIG. 17. As described above, thedisplay system 10 includes the detection device 700, the calculator 300,the display control device 400, the image generator 500, and thedisplayer 600. The display control device 400 has the obtainer 404 andthe controller 405. The functions of the controller 405 are the same asor similar to those of the determiner 401 and the display controller402. The constituent elements of the display system 10 will be describedbelow with reference to FIG. 17.

The detection device 700 detects a predetermined object that exists inthe surroundings of a movable body. The detection device 700 has atleast a sensor 100. The detection device 700 may also have a recognizer200. Thus, a detection result of the detection device 700 includes atleast a sensing result. The detection device 700 senses the surroundingsof the vehicle at predetermined time intervals. Whether or not apredetermined object is to be recognized based on the surroundingsinformation of the movable body, the surroundings information being asensing result, is determined based on the specifications of thedetection device 700. When the detection device 700 is to recognize apredetermined object, the detection device 700 recognizes apredetermined object on the basis of the surroundings information. Amethod for recognizing an object is the same as or similar to thatdescribed above.

The calculator 300 calculates a detection accuracy of the detectiondevice 700. The detection accuracy is analogous to the recognitionaccuracy. The calculator 300 outputs detection accuracy informationindicating a detection accuracy value to the display control device 400.Since a method for calculating the detection accuracy is the same as orsimilar to that described above, a description thereof is not givenhereinafter.

The obtainer 404 in the display control device 400 obtains the detectionaccuracy from the calculator 300. When the display control device 400 isimplemented by hardware, the obtainer 404 is an input portion, forexample, a connector and an input terminal.

As described above, the controller 405 has functions that are the sameas or similar to those of the determiner 401 and the display controller402. That is, on the basis of the detection accuracy, the controller 405controls the image generator 500 so as to generate a predetermined imagethat shows a graphic having a predetermined shape when displayed on adisplay medium.

On the basis of the control information from the display controller 402,the image generator 500 generates the predetermined image. Thepredetermined image is displayed on a display medium by the displayer600 described below and shows a graphic having a predetermined shape.Display examples of the graphic having a predetermined shape aredescribed later with reference to FIGS. 7A to 8D. The predeterminedimage may be an image or may be image data. When the displayer 600described below has a projector function, the image generator 500generates an image, and the displayer 600 projects the image. On theother hand, when the displayer 600 described below does not have aprojector function, the image generator 500 generates image data, andthe displayer 600 outputs the image data.

The displayer 600 outputs the predetermined image, generated by theimage generator 500, onto a display (which is not illustrated and is oneexample of a display medium) to thereby display the graphic having apredetermined shape on the display medium. The displayer 600 has, forexample, a projector function and directly projects the graphic onto thedisplay. The display is, for example, the front windshield of a movablebody or a transparent combiner (e.g., the combiner 801 illustrated inFIG. 20) provided separately from the windshield. That is, the displayer600 displays a graphic having a predetermined shape on the windshield byprojecting a predetermined image onto the windshield. The occupant inthe movable body views the displayed graphic having a predeterminedshape as a virtual image.

FIG. 21 is a flowchart illustrating an example operation of the displaycontrol device 400 included in the display system 10 illustrated in FIG.17. An example operation of the controller 405 will be described belowwith reference to FIGS. 17 and 21.

In step S101, when the obtainer 404 obtains the detection accuracy (YESin step S101), the flow proceeds to step S102 in which the controller405 determines whether the recognition accuracy is high or low on thebasis of the detection accuracy and a pre-defined threshold. When theobtainer 404 does not obtain the detection accuracy (NO in step S101),the flow ends.

When the detection accuracy is higher than or equal to the threshold instep S102, the controller 405 determines that the detection accuracy isa high accuracy (YES in step S102). In this case, the flow proceeds tostep S103. On the other hand, when the detection accuracy is lower thanthe threshold in step S102, the controller 405 determines that thedetection accuracy is a low accuracy (NO in step S102). In this case,the flow proceeds to step S104.

In step S103, the controller 405 sets the division number to n (n is aninteger greater than or equal to 2).

In step S104, the controller 405 determines that the graphic is not tobe divided or sets the division number to m (m is an integer that isgreater than or equal to 2 and that is smaller than n).

Specific examples of the division-number setting process and thedividing-method determination process in steps S103 and S104 aresubstantially the same as those described above with reference to FIGS.4 to 6F.

Next, in step S105, the controller 405 controls the image generator 500so as to generate a predetermined image. The “predetermined image” asused in this case refers to an image that shows a graphic having apredetermined shape when displayed on a display medium. The graphichaving a predetermined shape may be any of the graphics described abovewith reference to FIGS. 4 to 6F.

For example, upon setting the division number to n in step S103, thecontroller 405 controls the image generator 500 so as to generate apredetermined image that shows a graphic divided into n regions by usingthe determined dividing method. On the other hand, upon determining thatthe division is not to be performed or setting the division number to min step S103, the controller 405 controls the image generator 500 so asto generate a predetermined image that shows an undivided graphic or agraphic divided into m regions by using the determined dividing method.

Next, in step S106, under the control of the controller 405, the imagegenerator 500 generates the predetermined image.

Next, in step S107, the displayer 600 outputs the predetermined image,generated by the image generator 500, onto a display medium to therebydisplay the graphic having a predetermined shape on the display medium.The flow then returns to step S101.

As described above, the detection device 700 detects a predeterminedobject that exists in the surroundings of a movable body, and thecalculator 300 calculates the detection accuracy of the detection device700. The image generator 500 generates a predetermined image, and thedisplayer 600 outputs the predetermined image onto a display medium tothereby display a graphic having a predetermined shape on the displaymedium. The display control device 400 has the obtainer 404 forobtaining the detection accuracy and the controller 405 for controlling,on the basis of the detection accuracy, the image generator 500 so as togenerate a predetermined image that shows a graphic having apredetermined shape when displayed on the display medium. When theobtainer 404 obtains a first detection accuracy (a high accuracy), thecontroller 405 controls the image generator 500 so as to generate afirst predetermined image that shows a first graphic having apredetermined shape and divided into n regions when displayed on thedisplay medium. When the obtainer 404 obtains a second detectionaccuracy (a low accuracy) that is lower than the first detectionaccuracy (the high accuracy), the controller 405 controls the imagegenerator 500 so as to generate a second predetermined image that showsa second graphic having a predetermined shape and divided into m regionsor undivided when displayed on the display medium. In this case, n is aninteger greater than or equal to 2, and m is an integer that is greaterthan or equal to 2 and that is smaller than n.

Ideally, the predetermined image is the same as the graphic having apredetermined shape. Although the predetermined image and the graphichaving a predetermined shape are somewhat different from each otherdepending on the conditions, such as the degree of curvature of thedisplay medium, they are substantially the same. The predetermined imageis generated by the image generator 500, and the graphic having apredetermined shape is displayed on the display medium. Thehighlighted-region setting described above with reference to FIGS. 7A to7D may also be performed only when an object for which caution is to begiven exists in the surroundings of the vehicle. That is, in the displaysystem 10 in the present embodiment, setting the highlighted region anddisplaying the highlighted region on a display medium is not essentialprocessing. Any processing may be used as long as a graphic having apredetermined shape is displayed on a display medium on the basis of thedetection accuracy.

FIG. 22 illustrates a processing flow of the display system 10illustrated in FIG. 17, when the display system 10 displays a graphichaving a predetermined shape on a display medium upon recognizing apredetermined object that exists in the surroundings of a movable body.The processing flow will be described below.

In step S111, when the detection device 700 recognizes a predeterminedobject that exists in the surroundings of the movable body (YES in stepS111), the flow proceeds to step S112. When the detection device 700does not recognize a predetermined object (NO in step S111), the flowends.

In step S112, the calculator 300 calculates the detection accuracy, andthen the flow proceeds to step S102. Since the subsequent processes aresubstantially the same as those in FIG. 21, descriptions thereof are notgiven hereinafter.

The graphic having a predetermined shape does not necessarily have to beequally divided. For example, the graphic does not necessarily have tobe equally divided at the left and right sides, as illustrated in FIGS.23A and 23B. For example, when the detection device 700 is a camera,there is the possibility that the recognition accuracy decreasespartially at the front left side of the vehicle, the front right side ofthe vehicle, or the like, depending on sunlight conditions, such asshade. In accordance with the recognition accuracies that differ fromone place to another, the detection device 700 may also change thedivision number of a portion of the graphic having a predeterminedshape, rather than changing the division number of the entire graphic.FIG. 23A illustrates a display example when the recognition accuracy forthe front right side, viewed from the vehicle, has decreased and thedisplay resolution for only the front right side has decreased. On theother hand, FIG. 23B illustrates a display example when the recognitionaccuracy for the front left side, viewed from the vehicle, has decreasedand the display resolution for only the front left side has decreased.

Also, the division of the graphic having a predetermined shape may beonly sectioned with a dashed line(s), as illustrated in FIGS. 24A to 24Dand FIGS. 25A to 25D. In addition, the lines may not only be the dashedlines, but also be solid lines, dashed-dotted lines, or dotted lines.

Additionally, the graphic having a predetermined shape is not limited toa circular-sector shape and may be a linear shape substantially parallelto the horizontal axis, as illustrated in FIGS. 18A to 18C. This isbecause, even with the linear shape, it is possible to recognize thedirection of a predetermined object that exists in the surroundings of amovable body. FIG. 18A illustrates a state in which a graphic is notdivided, and FIGS. 18B and 18C illustrate states in which a graphic isdivided.

In the above description, the display device 20 has been described ashaving the display control device 400, the image generator 500, and thedisplayer 600. However, when the display medium is a combiner, thedisplay device 20 may also have the display medium. FIG. 20 illustratesan example configuration of the display device 20 when the displaymedium is a combiner. The display device 20 has the combiner 801 servingas a display medium.

As described above, the present embodiment has the feature that thegraphic indicating the recognition accuracy is displayed on the displayat all times, and the division number of the graphic is changedaccording to the recognition accuracy. This allows the driver of thevehicle to intuitively recognize the recognition accuracy at all times.As a result, the driver can perform driving and operation withoutexcessively relying on the display system.

Also, the present embodiment has a feature that, even when the results(e.g., the relative angles or the distances) of the object recognitionperformed by the recognizer are the same, the division number of thegraphic and the position of the highlighted region are changed accordingto the recognition accuracy. As a result, the direction in which anobject exists or the distance between an object and the vehicle can bedisplayed with a low resolution when the recognition accuracy is low orcan be displayed with a high resolution when the recognition accuracy ishigh.

Although the first embodiment of the present disclosure has beendescribed thus far, the present disclosure is not limited to the firstembodiment, and various modifications are possible thereto.Modifications will be described below.

Modification 1

Although the second graphic to be divided is semicircular (see e.g., thegraphic 302 in FIG. 4) in the embodiment described above, the shape ofthe second graphic is not limited thereto. For example, use of a sensorthat can sense the sides and rear of the vehicle in addition to thefront of the vehicle as the sensor 100 makes it possible to detectobjects in all directions in the surroundings of the vehicle. In thiscase, the displayer 600 may also use, for example, an annular graphic802 (one example of the second graphic) indicating the vehicle and itssurroundings in all directions, as illustrated in FIGS. 9A and 9B. Forexample, when the relative angle is used to set a highlighted region,and the recognition accuracy is a low accuracy, the display controller402 sets the division number to 4 (m=4) and then determines a dividingmethod for dividing the graphic 802 into four regions by using divisionstraight lines 803 passing through the graphic 301, as illustrated inFIG. 9A. When the displayer 600 executes this dividing method, thegraphics are displayed on the display, as illustrated in FIG. 9B or 9C.Also, for example, when the relative angle is used to set thehighlighted region, and the recognition accuracy is a high accuracy, thedisplay controller 402 sets the division number to 6 (n=6) and thendetermines a dividing method for dividing the graphic 802 into sixregions by using division straight lines 803 passing through the graphic301, as illustrated in FIG. 9D. When the displayer 600 executes thisdividing method, the graphics are displayed on the display, asillustrated in FIG. 9E or 9F.

Modification 2

When the distance is used to set the highlighted region, for example, apolygonal graphic 902 may also be used as the second graphic to bedivided, as illustrated in FIGS. 10A and 10B. For example, when therecognition accuracy is a low accuracy, the display controller 402 setsthe division number to 2 (m=2) and then determines a dividing method fordividing the graphic 902 into two regions by using a division straightline 903 extending in a direction orthogonal to the vehicle travelingdirection (indicated by the front edge of the graphic 301), asillustrated in FIG. 10A. When the displayer 600 executes this dividingmethod, the graphics are displayed on the display, as illustrated inFIG. 10B or 10C. Also, for example, when the recognition accuracy is ahigh accuracy, the display controller 402 sets the division number to 3(n=3) and then determines a dividing method for dividing the graphic 902into three regions by using division straight lines 903 orthogonal tothe vehicle traveling direction, as illustrated in FIG. 10D. When thedisplayer 600 executes this dividing method, the graphics are displayedon the display, as illustrated in FIG. 10E or 10F.

Modification 3

Although the description in the above embodiment has been given of anexample in which the first dividing method is executed when the relativeangle is used to set the highlighted region and the second dividingmethod is executed when the distance is used to set the highlightedregion, the present disclosure is not limited thereto. For example, boththe relative angle and the distance may also be used to set thehighlighted region. In such a case, the first dividing method and thesecond dividing method may also be combined together. For example, whenthe recognition accuracy is a low accuracy, the display controller 402determines a dividing method for dividing the graphic 302 into threeregions by using division straight lines 303 and dividing the graphic302 into two regions by using a division curve line 304, as illustratedin FIG. 11A. When the displayer 600 executes this dividing method, thegraphics are displayed on the display, as illustrated in FIG. 11B or11C. Also, for example, when the recognition accuracy is a highaccuracy, the display controller 402 determines a dividing method fordividing the graphic 302 into five regions by using division straightlines 303 and dividing the graphic 302 into three regions by usingdivision curve lines 304, as illustrated in FIG. 11D. When the displayer600 executes this dividing method, the graphics are displayed on thedisplay, as illustrated in FIG. 11E or 11F. Although the highlightedregion is not illustrated in FIGS. 11A to 11F, it may be displayedthrough processing as described below. For example, when both therelative angle and the distance have high accuracies, one of the regionsdivided by the division straight lines 303 and the division curve lines304 illustrated in FIG. 11D may also be displayed as a highlightedregion. Also, for example, when the distance has a low accuracy and therelative angle has a high accuracy, the graphic 302 is divided intothree regions in the circumferential direction, as illustrated in FIG.11A, with respect to the distance, and the graphic 302 is divided intofive regions by using straight lines passing through the graphic 301, asillustrated in FIG. 11D, with respect to the relative angle, and thenone of the divided regions may be set as a highlighted region.

Modification 4

In order to further enhance the recognition accuracy, for example, thedisplay system 10 may also be configured to have a plurality of types ofsensors, such as a millimeter-wave sensor, a camera, and a laser radar,as the sensor 100. In this case, the calculator 300 may calculate therecognition accuracy such that the larger the number of types of sensorsthat operate, the higher the recognition accuracy is. The calculator 300may also calculate the recognition accuracy on the basis of the numberof sensors that are operating properly or the number of sensors that areout of order among the plurality of sensors.

Modification 5

When the division number of the second graphic is changed according tothe recognition accuracy, this means that the display area of thehighlighted region changes. The area of the highlighted region is notintended to indicate the degree of risk (the possibility that thevehicle collides with an object, also called the degree of urgency).However, for example, when the area of the highlighted region increases,it may give the occupant an erroneous impression, that is, an impressionthat the degree of risk has increased. Accordingly, when the area of thehighlighted region changes from a small area to a large area, thedisplay controller 402 may perform control such that the luminance ofthe highlighted region after the change is lower than the luminance ofthe highlighted region before the change. For example, when therecognition accuracy decreases during display of the graphicsillustrated in FIG. 7D, and the graphics being displayed are switched tothe graphics illustrated in FIG. 7B, the display controller 402 performscontrol such that the luminance of the region 603 is lower than theluminance of the region 607. On the other hand, when the area of thehighlighted region changes from a large area to a small area, thedisplay controller 402 may perform control such that the luminance ofthe highlighted region after the change is higher than the luminance ofthe highlighted region before the change. For example, when therecognition accuracy increases during display of the graphicsillustrated in FIG. 7B, and the graphics being displayed are switched tothe graphics illustrated in FIG. 7D, the display controller 402 performscontrol such that the luminance of the region 607 is higher than theluminance of the region 603. As a result of such control, it is possibleto avoid giving the occupant the above-noted erroneous impression.

Modification 6

Although, in the above embodiment, the position of the highlightedregion is determined according to the relative angle during setting ofthe highlighted region, a method that is different therefrom may also beused to set the highlighted region. An example of such a method will bedescribed with reference to the graphics illustrated in FIG. 7B. Forexample, when the vehicle is traveling in the center lane of threeparallel lanes, and another vehicle is traveling ahead in the same laneas an object to be recognized, the display controller 402 sets thehighlighted region to the region 602. When another vehicle is travelingahead in the right lane, the display controller 402 sets the highlightedregion to the region 603. Also, when another vehicle is traveling aheadin the left lane, the display controller 402 sets the highlighted regionto the region 601.

Modification 7

Although, in the above-described embodiment, the determiner 401 comparesthe recognition accuracy with the threshold to thereby make the binarydetermination as to whether the recognition accuracy is a high accuracyor low accuracy, the present disclosure is not limited thereto. Forexample, a plurality of thresholds may also be used to determine therecognition accuracy with three values or more. This makes it possibleto increase the number of patterns of the division number of the graphicand makes it possible to inform the driver of a more specificrecognition accuracy. The driver can also be more specifically informedof the direction in which an object exists and/or the distance to theobject.

Modification 8

Although the description in the above embodiment has been given of anexample in which the determiner 401 determines whether the accuracy ishigh or low and the display controller 402 sets the division number onthe basis of the accuracy determination, the present disclosure is notlimited thereto. For example, the determiner 401 may also set thedivision number. For example, the determiner 401 may set the divisionnumber on the basis of a table in which the recognition accuracy valuesand the division numbers are associated with each other and therecognition accuracy value from the calculator 300 and may output theset division number to the display controller 402 as the determinationresult information. Alternatively, for example, the determiner 401 maycalculate the division number by using a predetermined mathematicalexpression for calculating the division number from the recognitionaccuracy value calculated by the calculator 300 and may output thecalculated division number to the display controller 402 as thedetermination result information. The display controller 402 may also beconfigured so as to directly receive the recognition accuracy value fromthe calculator 300, to thereby allow the display controller 402 toperform the processing in this modification (in this case, thedeterminer 401 can be eliminated from the configuration).

Modification 9

The first graphic or the second graphic may be a graphic that isentirely painted with a predetermined color or may be a graphic whoseonly outline is colored with a predetermined color.

Modification 10

The color of the first graphic and/or the second graphic may also bechanged depending on whether or not an object is detected by the sensor100. For example, when no object is detected, the display controller 402displays the graphic by using a color (e.g., blue or green) that givesthe driver an impression that the degree of risk is low. On the otherhand, when an object is detected, the display controller 402 displaysthe graphic by using a color (e.g., yellow or red) that gives the driveran impression that the degree of risk is high.

Modification 11

The color of the highlighted region may also be changed according to thedistance. For example, the display controller 402 performs control so asto use yellow when the distance is larger than or equal to apredetermined value and so as to use red when the distance is smallerthan the predetermined value.

Modification 12

Even when the sensor 100 is of the same type, the range that can besensed is different from sensor to sensor. For example, when the sensor100 is a camera, it may have a small detection range (e.g., 10 degreeshorizontally at each side centered on the forward direction) or may havea large detection range (e.g., 30 degrees horizontally at each sidecentered on the forward direction), depending on a difference in thelens used. Accordingly, the overall shape of the second graphic may bechanged so as to indicate the sensing range. An example of such anarrangement will be described with reference to the graphic 302illustrated in FIG. 4. For example, when the sensing range is small, theangle of the graphic 302 is reduced to change the overall shape thereofto a more acute circular-sector shape. This allows the driver tointuitively recognize that the sensing range is small.

Modification 13

Although the description in the above embodiment has been given of anexample in which the display controller 402 determines the dividingmethod by using the division straight line(s) or the division curveline(s) in accordance with the set division number, the presentdisclosure is not limited thereto. For example, the display controller402 (or a storage unit, not illustrated) may hold the second graphicdivided by a predetermined division number as a template. In such acase, the display controller 402 selects a template corresponding to thedetermination result of the determiner 401, as appropriate.

Modification 14

For example, when the recognizer 200 recognizes a plurality of objects,the calculator 300 and the determiner 401 may calculate and determinethe recognition accuracies for the respective objects. In addition, forexample, in accordance with the calculated recognition accuracy and thedetermined recognition accuracy of an object whose recognition accuracyis lower, the display controller 402 may perform the division-numbersetting and the dividing-method determination of the second graphic andthe highlighted-region setting.

Modification 15

Only the second graphic (e.g., the graphic 302) may be displayed withoutdisplaying the first graphic (e.g., the graphic 301).

Second Embodiment

A second embodiment of the present disclosure will be described withreference to FIG. 12. FIG. 12 is a block diagram illustrating an exampleconfiguration of the display system 10 according to the presentembodiment. FIG. 12 is different from FIG. 1 in that the display system10 further has a sensor 101 and does not have the recognizer 200 and thecalculator 300. Since constituent elements in FIG. 12 are the same as orsimilar to those described with reference to FIG. 1, detaileddescriptions thereof are not given hereinafter.

The sensor 100 is, for example, a sensing camera. The sensor 100 detectsthe surroundings of a vehicle and outputs a result of the detection tothe determiner 401.

The sensor 101 is, for example, a raindrop sensor or an illuminancesensor and can detect a driving environment in which the recognitionaccuracy is likely to decrease (e.g., whether or not the vehicle istraveling in bad weather, such as in rain, fog, sleet, hail, or snow,whether or not the illuminance in the surroundings of the vehicle isincreased due to backlight, the headlights of an oncoming vehicle, orthe like, or whether or not the illuminance in the surroundings of thevehicle is reduced due to traveling at night or in a tunnel). The sensor101 detects bad weather due to rain, fog, or snow or an illuminancechange due to backlight, illumination light from another vehicle,traveling at night, or traveling in a tunnel and outputs a result of thedetection to the determiner 401.

When the sensor 101 does not detect bad weather or an illuminancechange, the determiner 401 determines that the recognition accuracy ofthe sensor 100 is a first recognition accuracy. Also, when the sensor101 detects bad weather or an illuminance change, the determiner 401determines that the recognition accuracy of the sensor 100 is a secondrecognition accuracy lower than the first recognition accuracy.

When the determiner 401 determines that the recognition accuracy of thesensor 100 is the first recognition accuracy, the display controller 402controls the image generator 500 so as to generate a predetermined imagethat shows a graphic having a predetermined shape, divided into nregions (n is an integer greater than or equal to 2), and indicating apositional relationship between the predetermined object and thevehicle, when displayed on a display medium. Also, when the determiner401 determines that the recognition accuracy of the sensor 100 is thesecond recognition accuracy, the display controller 402 controls theimage generator 500 so as to generate a predetermined image that shows agraphic having a predetermined shape and undivided or divided into mregions (m is an integer that is greater than or equal to 2 and that issmaller than n) when displayed on a display medium.

As described above, the present embodiment can offer substantially thesame advantages as those in the first embodiment described above. Themodifications described in the first embodiment may also be applied tothe present embodiment, as appropriate.

Third Embodiment

A third embodiment of the present disclosure will be described withreference to the accompanying drawings.

When the division number of the graphic is changed according to therecognition accuracy, if the deletion of a second graphic beingdisplayed and the display of a next second graphic to be displayed aresimultaneously performed, large changes occur in the imageinstantaneously, and thus the driver experiences annoyance. Accordingly,in the present embodiment, when the division number of the graphic ischanged according to the recognition accuracy, control is performed sothat deletion of a second graphic being displayed and the display of anext second graphic to be displayed are changed in a time series.

First, a description will be given of an example configuration of adisplay system 10 according to the present embodiment. FIG. 13 is ablock diagram illustrating an example configuration of the displaysystem 10 according to the present embodiment. FIG. 13 is different fromFIG. 1 in that the display control device 400 further has a displaycorrector 403. In FIG. 13, constituent elements that are the same as orsimilar to those in FIG. 1 are denoted by the same reference numerals,and descriptions thereof are not given hereinafter.

When there is a change between the division number of the second graphicbeing displayed (hereinafter referred to as a “graphic being displayed”)and the division number of a next second graphic to be displayed(hereinafter referred to as a “latest graphic”), the display corrector403 corrects the control information from the display controller 402 andoutputs the corrected control information to the image generator 500.The corrected control information includes information for causing theimage generator 500 to execute control for causing the deletion of thegraphic being displayed and the display of the latest graphic to bechanged in a time series. A detailed operation of the display corrector403 is described later with reference to FIG. 14.

Next, a description will be given of an example operation of the displaysystem 10 according to the present embodiment. FIG. 14 is a flowchartillustrating an example operation of the display system 10 according tothe present embodiment.

In step S011, the display corrector 403 obtains the latest controlinformation from the display controller 402. This control informationincludes, for example, the shape of the latest graphic, the divisionnumber, the dividing method, and the highlighted region.

In step S012, the display corrector 403 compares the division numberincluded in the control information for the graphic being displayed withthe division number included in the latest control information todetermine whether or not there is a change between the division numbers.It is assumed that the control information for the graphic beingdisplayed is stored by the display corrector 403 before it obtains thelatest control information.

When the result of the determination processing in step S012 indicatesthat there is no change between the division numbers (NO in step S012),the display corrector 403 does not correct the latest controlinformation, outputs the latest control information to the imagegenerator 500, and newly stores the latest control information.Thereafter, the flow proceeds to step S016.

On the other hand, when the result of the determination processing instep S012 indicates that there is a change between the division numbers(YES in step S012), the flow proceeds to step S013.

In step S013, the display corrector 403 calculates a time that haselapsed from the time when the latest control information was obtained(this time is hereinafter referred to simply as “elapsed time”).

In step S014, in accordance with the elapsed time, the display corrector403 sets a luminance of the graphic being displayed. FIG. 15Aillustrates a specific example of this setting. As illustrated in FIG.15A, the display corrector 403 performs setting so that the luminance(relative value) of the graphic being displayed decreases gradually inaccordance with the elapsed time.

In step S015, the display corrector 403 sets a luminance of the latestgraphic in accordance with the elapsed time. FIG. 15B illustrates aspecific example of this setting. As illustrated in FIG. 15B, thedisplay corrector 403 performs setting so that the luminance (relativevalue) of the latest graphic increases gradually in accordance with theelapsed time.

After setting the luminance, the display corrector 403 outputsinformation including the control information for the graphic beingdisplayed, the latest control information, the luminance set in stepS014, and the luminance set in step S015 to the image generator 500 asthe corrected control information. Also, the display corrector 403 newlystores the latest control information.

In step S016, on the basis of the control information from the displaycorrector 403, the displayer 600 generates a graphic and displays thegraphic on the display. For example, when the result of thedetermination processing in step S012 indicates that there is no changebetween the division numbers, a graphic is generated and displayed basedon the un-corrected latest control information. On the other hand, whenthe result of the determination processing in step S012 indicates thatthere is a change between the division numbers, a graphic is generatedand displayed based on the corrected control information. A specificexample of this case is illustrated in FIG. 15C. For example, when therecognition accuracy decreases during display of the graphic illustratedin FIG. 7D (one example of the graphic being displayed), and the graphicbeing displayed is switched to the graphic illustrated in FIG. 7B (oneexample of the latest graphic), display is performed so that theluminance of the graphic in FIG. 7D decreases gradually, and theluminance of the graphic in FIG. 7B increases gradually, in accordancewith the elapsed time, as illustrated in FIG. 15C.

As described above, the present embodiment has the feature that controlfor causing the deletion of the graphic being displayed and the displayof the latest graphic to be changed in a time series is performed whenthe division number of the graphic is changed according to therecognition accuracy. With this arrangement, the graphic is seen suchthat the graphic being displayed disappears gradually and the latestgraphic appears gradually, thus making it possible to reduce theannoyance experienced by the driver.

Although the third embodiment of the present disclosure has beendescribed above, the present disclosure is not limited to the thirdembodiment described above, and various changes and modifications can bemade thereto. For example, each modification described above in thefirst embodiment and/or the second embodiment may also be applied to thethird embodiment, as appropriate.

The functions of the individual constituent elements in the displaysystem 10 and the display control device 400 in each embodimentdescribed above can also be implemented by a computer program.

FIG. 16 is a block diagram illustrating a hardware configuration of acomputer that realizes the functions of the individual constituentelements by using a program. This computer 1000 includes an input device1001, such as an input button and/or a touch pad, an output device 1002,such as a display or a speaker, a central processing unit (CPU) 1003, aread only memory (ROM) 1004, a random access memory (RAM) 1005, astorage device 1006, such as a hard-disk device or a solid-state drive(SSD), a reading device 1007 for reading information from a storagemedium, such as a digital versatile disk read-only memory (DVD-ROM) or aUniversal Serial Bus (USB) memory, and a transmission/reception device1008 for performing communication over a network. These elements areconnected through a bus 1009.

The reading device 1007 reads a program for realizing the functions ofthe constituent elements described above from a storage medium on whichthe program is recorded, and the read program is stored in the storagedevice 1006. Alternatively, the transmission/reception device 1008communicates with a server apparatus connected to the network,downloads, from the server apparatus, a program for realizing thefunctions of the constituent elements described above, and stores thedownloaded program in the storage device 1006.

The CPU 1003 copies the program stored in the storage device 1006 to theRAM 1005, sequentially reads instructions included in the program fromthe RAM 1005, and executes the instructions to thereby realize thefunctions of the constituent elements described above. Also, duringexecution of the program, information resulting from the variousprocesses described above in each embodiment is stored in the RAM 1005or the storage device 1006 and is used, as appropriate.

The present disclosure is useful for a display control device and adisplay control program that control display of information provided toa user (e.g., an occupant in a vehicle or the like or a user wearing adisplay device).

The functional blocks used in the description of the above embodimentsmay be realized in the form of a large scale integration (LSI), which isan integrated circuit. The functional blocks may be individuallyintegrated into single chips or at least one or all of the functionalblocks may be integrated into a single chip. Although the functionalblocks are implemented in the form of an LSI in this case, they may alsobe called an integrated circuit (IC), a system LSI, a super LSI, or anultra LSI depending on the difference in the degree of integration.

The scheme for integrating the functional blocks into an integratedcircuit is not limited to a scheme for LSI and may be realized with adedicated circuit or a general-purpose processor. The functional blockscan also be implemented using a field programmable gate array (FPGA)that can be programmed after manufacture of an LSI or a reconfigurableprocessor that allows reconfiguration of connections and settings ofcircuit cells in an LSI.

In addition, when a technology for circuit integration that replaces LSIbecomes available with the advancement of semiconductor technology oranother derivative technology, such a technology may also naturally beused to integrate the functional blocks. For example, biotechnology isapplicable to the integration.

What is claimed is:
 1. A display control device in a display systemincluding a detection device that detects a predetermined object thatexists in surroundings of a movable body, a calculator that calculates adetection accuracy of the detection device, an image generator thatgenerates a predetermined image, and a displayer that outputs thepredetermined image on a display medium to display a graphic having apredetermined shape on the display medium, the display control devicecomprising: an obtainer that obtains the detection accuracy; and acontroller that controls, based on the detection accuracy, the imagegenerator so as to generate the predetermined image that shows thegraphic having a predetermined shape when displayed on the displaymedium, wherein the controller controls the image generator so as togenerate a first predetermined image as the predetermined image, whenthe obtainer obtains a first detection accuracy, and controls the imagegenerator so as to generate a second predetermined image as thepredetermined image, when the obtainer obtains a second detectionaccuracy lower than the first detection accuracy, wherein the firstpredetermined image shows, as the graphic having a predetermined shape,a first graphic divided into n regions when displayed on the displaymedium, and the second predetermined image shows, as the graphic havinga predetermined shape, a second graphic divided into m regions orundivided when displayed on the display medium, and n is an integergreater than or equal to 2, and m is an integer that is greater than orequal to 2 and that is smaller than n.
 2. The display control deviceaccording to claim 1, wherein the display medium is a windshield of themovable body; and the displayer displays the graphic having apredetermined shape on the windshield by projecting the predeterminedimage onto the windshield.
 3. The display control device according toclaim 1, wherein the display medium is a transmissive display, and thepredetermined image is image data; and the displayer displays thegraphic having a predetermined shape on the transmissive display byoutputting the image data onto the transmissive display.
 4. The displaycontrol device according to claim 1, wherein the graphic having apredetermined shape includes a region indicating a positionalrelationship between the movable body and the predetermined object. 5.The display control device according to claim 4, wherein the graphichaving a predetermined shape is a graphic divided into a plurality ofregions by one or more lines extending radially from a predeterminedreference point; and the plurality of regions include a first regionindicating a direction in which the predetermined object exists relativeto the movable body and one or more second regions other than the firstregion, the first region being displayed in a first display mode, andthe one or more second regions being displayed in a second display modedifferent from the first display mode.
 6. The display control deviceaccording to claim 4, wherein, in the case where the graphic having apredetermined shape is displayed without being divided, the controllercontrols the image generator so as to generate the predetermined imagethat shows the predetermined shape in a first mode, when the detectiondevice recognizes the predetermined object, and controls the imagegenerator so as to generate the predetermined image that shows thepredetermined shape in a second mode when the detection device does notrecognize the predetermined object.
 7. The display control deviceaccording to claim 5, wherein, in the case where a division number ofthe graphic having a predetermined shape and displayed on the displaymedium changes owing to a change in the detection accuracy, thecontroller controls the image generator so that, when the first regionin the graphic having a predetermined shape increases owing to adecrease in the division number, luminance of the first region decreasescompared with the luminance thereof before the decrease in the divisionnumber, and controls the image generator so that, when the first regionin the graphic having a predetermined shape decreases owing to anincrease in the division number, the luminance of the first regionincreases compared with the luminance thereof before the increase in thedivision number.
 8. The display control device according to claim 1,wherein the graphic having a predetermined shape includes a regionindicating a distance between the predetermined object and the movablebody.
 9. The display control device according to claim 8, wherein thegraphic having a predetermined shape is a graphic divided into aplurality of regions by one or more lines that extend in a horizontaldirection or one or more lines that extend in an arc direction of acircle having a center at a predetermined reference point; and theplurality of regions include a third region indicating a distancebetween the movable body and the predetermined object and one or morefourth regions other than the third region, the third region beingdisplayed in a first display mode, and the one or more fourth regionsbeing displayed in a second display mode different from the firstdisplay mode.
 10. The display control device according to claim 8,wherein, when the graphic having a predetermined shape is displayedwithout being divided, the controller controls the image generator so asto generate the predetermined image that shows the predetermined shapein a first mode, when the detection device recognizes the predeterminedobject, and controls the image generator so as to generate thepredetermined image that shows the predetermined shape in a second modewhen the detection device does not recognize the predetermined object.11. The display control device according to claim 9, wherein, in thecase where a division number of the graphic having a predetermined shapeand displayed on the display medium changes owing to a change in thedetection accuracy, the controller controls the image generator so that,when the third region in the graphic having a predetermined shapeincreases owing to a decrease in the division number, luminance of thethird region decreases compared with the luminance thereof before thedecrease in the division number, and controls the image generator sothat, when the third region in the graphic having a predetermined shapedecreases owing to an increase in the division number, the luminance ofthe third region increases compared with the luminance thereof beforethe increase in the division number.
 12. The display control deviceaccording to claim 1, wherein, in the case where a division number ofthe graphic having a predetermined shape and displayed on the displaymedium changes owing to a change in the detection accuracy, thecontroller controls the image generator so as to display the graphichaving a predetermined shape by causing a mode of the graphic before thechange in the division number and a mode of the graphic after the changein the division number to be changed in a time series.
 13. The displaycontrol device according to claim 1, wherein the detection devicecomprises a first sensor that detects the surroundings of the movablebody and a second sensor that detects predetermined weather or anilluminance change; the detection accuracy is an accuracy of the firstsensor; when the second sensor does not detect the predetermined weatheror the illuminance change, the first detection accuracy is used as thedetection accuracy; and when the second sensor detects the predeterminedweather or the illuminance change, the second detection accuracy is usedas the detection accuracy.
 14. A display device, comprising: an obtainerthat obtains a detection accuracy of a detection device that detects apredetermined object that exists in surroundings of a movable body; acontroller that performs, based on the detection accuracy, control so asto generate a predetermined image that shows a graphic having apredetermined shape when displayed on a display medium; an imagegenerator that generates the predetermined image, based on controlperformed by the controller; and a displayer that displays the graphichaving a predetermined shape on the display medium by outputting thegenerated predetermined image onto the display medium, wherein thecontroller controls the image generator so as to generate a firstpredetermined image as the predetermined image, when the obtainerobtains a first detection accuracy, and controls the image generator soas to generate a second predetermined image as the predetermined image,when the obtainer obtains a second detection accuracy lower than thefirst detection accuracy, and wherein the first predetermined imageshows, as the graphic having a predetermined shape, a first graphicdivided into n regions when displayed on the display medium, and thesecond predetermined image shows, as the graphic having a predeterminedshape, a second graphic divided into m regions or undivided whendisplayed on the display medium, and n is an integer greater than orequal to 2, and m is an integer that is greater than or equal to 2 andthat is smaller than n.
 15. The display device according to claim 14,wherein the display medium is a windshield of the movable body; and thedisplayer displays the graphic having a predetermined shape on thewindshield by projecting the predetermined image onto the windshield.16. The display device according to claim
 14. wherein the display mediumis a transmissive display, and the predetermined image is image data;and the displayer displays the graphic having a predetermined shape onthe transmissive display by outputting the image data onto thetransmissive display.
 17. A display device according to claim 14,further comprising: a display medium; the controller that performs,based on the detection accuracy, control so as to generate apredetermined image that shows a graphic having a predetermined shapewhen displayed on the display medium; and the displayer that displaysthe graphic having a predetermined shape on the display medium byoutputting the generated predetermined image onto the display medium.18. A method of controlling a display system including a detectiondevice that detects a predetermined object that exists in surroundingsof a movable body, a calculator that calculates a detection accuracy ofthe detection device, an image generator that generates a predeterminedimage, and a displayer that outputs the predetermined image on a displaymedium to display a graphic having a predetermined shape on the displaymedium, the method comprising: controlling the image generator so as togenerate a first predetermined image as the predetermined image, whenthe detection accuracy calculated by the calculator is a first detectionaccuracy; controlling the image generator so as to generate a secondpredetermined image as the predetermined image, when the calculateddetection accuracy changes from the first detection accuracy to a seconddetection accuracy lower than the first detection accuracy, wherein thefirst predetermined image shows, as the graphic having a predeterminedshape, a first graphic divided into n regions when displayed on thedisplay medium, and the second predetermined image shows, as the graphichaving a predetermined shape, a second graphic divided into m regions orundivided when displayed on the display medium, and n is an integergreater than or equal to 2, and m is an integer that is greater than orequal to 2 and that is smaller than n.
 19. A non-transitorycomputer-readable storage medium storing a program for causing acomputer to execute the display control method according to claim 18.